Valence band offsets of Si/ZnS polar interfaces. A synchrotron radiation photoemission study

Synchrotron radiation photoelectron spectroscopy is used to measure the valence-band offsets for Si/ZnS(111) and (100) heterojunctions. The valence band discontinuities obtained from the measurements are both (1.9 +- 0.1) eV for Si/ZnS(111) and Si/ZnS(100) interfaces, which is in excellent agreement with the theoretical predictions but considerably different from the experimental result of ZnS/Si(111) reported by Maierhofer et al. This suggests that the commutativity rule of band offset may not be valid for Si/ZnS polar interface and the reason is discussed